An influenza A virus of H4N6 subtype was isolated from the Izumi plain, Japan, in 2013. Genetic analyses revealed that two viral genes (M and NS gene segments) of this isolate were genetically distinct from those of the H4N6 virus isolated from the same place in 2012. Furthermore, three viral genes (PB2, PB1 and M gene segments) of this isolate share high similarity with those of the North American isolates of 2014. These results suggest a high frequency of genetic reassortment of avian influenza viruses in Asian waterfowl and intercontinental movements of avian influenza viruses via migratory waterfowl.

We determined the complete genome sequences of torque teno sus viruses (TTSuVs) detected in pigs with postweaning multisystemic wasting syndrome (PMWS) and in healthy pigs in Japan. Unexpectedly, we found coinfection of a PMWS-affected pig in Japan with one strain of TTSuV1, five strains of TTSuV2, and one strain of PCV2. Full-genome sequencing of each of these strains, followed by phylogenetic analysis, revealed broad genetic diversity in the TTSuV2 strains infecting the PMWS-affected pig. These results suggest that the geographical bias in the available genetic information about TTSuVs has a limited impact on the evaluation of their genetic diversity.